.headbox{
    position: relative;
    overflow:hidden;
}


/* 视频背景 */
#background{
    position: absolute;
    left:0;
    top:0;
    min-width: 100%;
    width:100%;
    height: 100%;
    z-index:-100;
} 
#background img{
    width: 100%;
    height: 100%;
}
/* 头部 start */
.header{
    background:transparent;
    padding:2rem 0rem;
    overflow: hidden;
}

.header .box{
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 10;
}

.header .logo{
    font-family: Osb;
    color:#fff;
    font-size:2.5rem;
    cursor: pointer;
    transition: all linear .3s;
}

.header .logo:hover{
    text-shadow: 2px 2px 10px rgba(255,255,255,.5);
}


.header .nav{
    width:55%;
    display: flex;
    justify-content: space-between;
}

.header .nav a{
    display: inline-block;
    color:black;
    font-size:1rem;
    text-transform: uppercase;
    height:3rem;
    line-height:3rem;
    border-bottom:1px solid rgba(0,0,0,0);
    transition: all linear .2s;
    
}

.header .nav a:hover{
    border-bottom:1px solid #fcac45;
}

/* 移动端导航 */
.mobi{
    width:2.5rem;
    cursor: pointer;
    display: none;
}
.mobi span{
    display: block;
    width:2.5rem;
    height:.5rem;
    background:#fff;
    margin-bottom:.5rem;
}

@media screen and (min-width:600px) and (max-width:900px){
    .header .nav{
        width:73%;
    }
}

/* 媒体查询 兼容移动端 550 */
@media screen and (max-width:600px){
    .header .box{
        /* 允许换行 */
        flex-wrap: wrap;
        padding:0rem 1rem;
    }
    .mobi{
        display: block;
        transition: all linear .3s;
    }

    .header .nav{
        width:100%;
        opacity: 0;
        height:0;
        overflow:hidden;
        flex-wrap: wrap;
        transition: all linear .6s;
    }

    .header .nav a{
        display: block;
        width:100%;
        text-align: center;
    }

    .header .nav a:hover{
        text-shadow: 1px 1px 10px #fff;
        font-weight: bold;
        transform:scale(1.1);
    }

    #mobi:checked ~ label[for="mobi"]{
        transform:rotate(90deg);
    }

    #mobi:checked ~ .nav{
        height: auto;
        opacity: 1;
        z-index: 10;
        position: absolute;
        top: 6rem;
        left: 0;
        background:rgba(0, 0,0, 0.5);
        width: 100%;

    }

    
}

@media screen and (min-width:300px){
    .header{
        width: 100%;
        height: 100%;
        margin: 0 auto;
    }
}

/* 头部 end */



/* banner start */
.banner{
    padding:5rem 0rem 5rem;
    /* z-index: -1; */
}

.banner .title{
    text-transform: uppercase;
    font-family: Osl;
    color:#999;
    font-size:3rem;
    margin-bottom:.5rem;
}

.banner .title span{
    color:#fcac45;
    font-weight: bold;
    font-family: Osb;
}

.banner .desc{
    margin-bottom:5rem;
    color:#fff;
}
.banner .desc span{
    padding-left: 10px;
}

.down{
    width:3rem;
    height:3rem;
    margin:0 auto;
}

.down a{
    display: block;
    width:3rem;
    height:3rem;
    line-height:3rem;
    text-align: center;
    border:1px solid black;
    border-radius: 100%;
    color:black;
    font-weight: bold;
    user-select: none;
    transition: all linear .3s;
}

.down a:hover{
    transform:scale(1.1);
    box-shadow: 0px 0px 5px #c3c3c3;
}
/* banner end  */